What is the oxidation state of the potassium permanganate?
I assume the question refers to the oxidation number of manganese, or
If you're familiar with the rules for calculating oxidation numbers (more here: http://socratic.org/questions/how-do-you-calculate-oxidation-numbers), you'll notice immediately that each oxygen atom has an O.N. of -2 and that the potassium atom has an O.N. of +1.
As a side note, potassium permanganate is often used in experiments that show the color changes that accompany the reduction of manganese from +7 to +6, and from +6 to +4.
This is done by reacting
Here's a video on such an experiment: